Active Matrix Organic Light Emitting Diode (AMOLED) panel is more and more widely used. The pixel light-emitting units for AMOLED is organic light-emitting diode (OLED). AMOLED is driven by thin film transistors (TFTs) in a saturated state to generate a driving current, which drive the OLED to emit light. FIG. 1 is a schematic diagram showing a basic pixel driving circuit in the related art. As shown in FIG. 1, the basic pixel driving circuit employs a 2T1C circuit which includes two TFTs (a switching transistor T0 and a driving transistor DTFT), and a storage capacitor C.
However, in the conventional low-temperature polysilicon manufacturing process, the uniformity of the threshold voltage Vth of the respective drive transistors DTFT on the display substrate is poor, and drifts of the threshold voltages occur during application. In this way, when the switching transistor T0 is controlled by the scan line to be turned on so that a same data voltage Vdata is input to the respective driving transistors DTFTs, different driving currents are generated because the threshold voltages of the respective driving transistors DTFTs are different, resulting in poor luminance uniformity of the AMOLED panel.
In addition, OLED will gradually aging, so as to cause brightness attenuation of the OLED display, thereby affecting the user's use.